This invention relates generally to the field of materials construction and, more specifically, to an apparatus and method for constructing a composite structure.
Composite structures are desirable in many industries for many applications. For example, aircraft, space, and land/sea vehicles employ a variety of curved and multiple-contoured surface structures in their fabrication. Composite materials such as fiberglass/resin are commonly used for these structures because, among other desirable attributes, composite materials have high strength-to-weight ratios. Because of the ever-increasing use of composite structures throughout industry, manufacturers are continually searching for better and more economical ways of forming composite structures.
In the forming of composite structures many manufacturing steps are performed. One such step that is usually required is a curing step. During the cure process, composites must be formed over tooling that restrains them. These tools are generally monolithic dies that are machined or cast from a solid block to conform to a specific surface shape and, therefore, cannot have their shape modified once created. Subsequent structures having different surface shapes, though similar, must have a new tool fabricated. This is a source of manufacturing time and expense. In addition, such monolithic dies are bulky, require much setup time at the form press prior to commencement of manufacturing, and utilize large amounts of storage space when not in a production mode. Present solutions attempting to resolve this problem have relied on metallic tooling surfaces that can be reconfigured. They utilize articulating sections, sliding pins, and other methods to change the shape of the tooling surface. These methods can leave dimples on the surface of the finished structure due to the nature of the reconfigurable elements. To alleviate the problem of dimpling, manufacturers employ many reconfigurable elements spaced very close to one another. However, the more hardware, the greater the expense and maintenance. Furthermore, structure size can be limited by these methods since scale-up can be cumbersome and expensive. And when large quantities of various contoured surface structures are required, each structure would require a separate rigid surface tool and would have to be durable enough for a production run. Lower cost tooling material options such as foam, which can be easily machined to create a family of tools, do not have the desired durability and each would require its own support base adding to the tool""s cost.
The challenges in the field of materials construction have continued to increase with demands for more and better techniques having greater flexibility and adaptability. Therefore, a need has arisen for a new apparatus and method for constructing a composite structure.
In accordance with the present invention, an apparatus and method for constructing a composite structure is provided that substantially eliminates or reduces disadvantages and problems associated with previously developed apparatuses and methods.
An apparatus for constructing a composite structure is disclosed. The apparatus comprises a flexible layer, which has a working surface and an underside surface, coupled to a base. At least one support element is coupled to the underside surface of the flexible layer, and at least one adjustable element is coupled to the support element for adjusting the position of the flexible layer. More specifically, the flexible layer may have internal reinforcing elements for added strength and durability.
A method for constructing a composite structure is disclosed. The method comprises four steps. Step one calls for coupling a flexible layer to a base, where the flexible layer has a working surface and an underside surface. Step two requires coupling at least one support element to the underside surface of the flexible layer. The next step calls for coupling at least one adjustable element to the support element for adjusting the position of the flexible layer. The last step requires configuring the flexible layer to a configuration suitable for constructing the composite structure. More specifically, the flexible layer may have internal reinforcing elements for added strength and durability.
A technical advantage of the present invention is to provide a durable tool surface that can be quickly reconfigured to produce a myriad of contoured surface structures, including prototypes for demonstration programs.
Another technical advantage of the present invention is that the flexible layer has internal reinforcing rods that have the ability to slide within the flexible layer""s volume, thus permitting the flexible layer to be stretched in the plane of the material while resisting flexure in the direction perpendicular to the material. The rods support the flexible layer as it is being manipulated perpendicular to the plane of the material. This insures that a uniform surface curvature can be generated in the flexible material. In addition, the internal reinforcing rods, combined with the support elements underneath the flexible layer, help to avoid any xe2x80x9cpillowing effectxe2x80x9d of the flexible layer between the support elements. The reinforcing rods also increase the strength and durability of the forming tool.
A further technical advantage is that the present invention can be used for the construction of room temperature cured composites having large length and width dimensions. This is because there are no constraints such as the tool being able to fit inside of an autoclave.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.